This invention relates to the accessing of different and distinct cellular/wireless (C/W) telephone network/systems with a particular cellular/wireless (C/W) telephone instrument not necessarily adapted to operation in any one of the particular systems. Access is consummated by means of adapting an interface with the system requirements through adaptation of processing procedures of the cellular/wireless network/system alone. In particular the network adaptation process granting access and functionality is attuned for a C/W telephone instrument in response to entries transmitted to the network system from the C/W telephone instrument.
A normal cellular/wireless (C/W) telephone instrument is designed to operate only with a particular cellular/wireless (C/W) communication network/system and as such is designed in accord with interface requirements specific to the network/system sought to be accessed. Such requirements include modulation schemes, format, signal structure, link protocols, signal waveforms and signal frequencies. These are all unique to each network/system and a cellular/wireless telephone instrument designed to work in one cellular/wireless network/system will not function in another C/W network/system having a different operating environment.
Traveling subscribers, particularly international travelers are impacted by inoperability of cellular/wireless telephone instruments in a different C/W system, particularly in international travel. In some instances a cellular/wireless telephone instrument is designed to be operative in more than one cellular/wireless/network/system. An example is cellular/cordless telephone instruments which operate in either a cellular or cordless medium. Such a telephone instrument however carries a large over head of redundant design and feature amenities. As a result such a telephone instrument is expensive and may even be unwieldy in size in order to support all the various features so that the user may properly interact with the different systems.
Several prior efforts have been made to accommodate the various dilemma of the traveling telephone user. A common dilemma is the different operating parameters and operating characteristics of C/W telephone instruments associated with different C/W networks. One solution to these dilemma has been to provide a xe2x80x9cuniversalxe2x80x9d telephone instrument associated with a network/system that accepts a database encoded on a card (e.g., a smartcard) to control and/or modify telephone instrument operations. This causes the telephone instrument to operate in a manner identical with operations that the user is used to in his home network/system.
Universal telephone instruments, for example, are associated with a particular network but can be programmed to mimic responses of a telephone instrument associated with a different telephone network. They often include a smartcard reader to provide a database for such purpose. The foreign user inserts a smartcard into the telephone instrument. It includes all the data as to how the telephone instrument should appear to the user, what language to use, how it should respond and how it is operated in order to make it conform to a telephone instrument that the user is accustomed to. A database of this operational information may be contained solely on the smartcard or it may be included in a database located in the universal telephone instrument. Such a technique is disclosed in U.S. Pat. No. 5,878,124, which also provides an overlay device to the telephone instrument to provide the home appearance and functions that the user is accustomed to. In this arrangement the universal telephone instrument is a specialized telephone instrument which must be provided by the system the user is attempting to access. It does not concern a cellular/wireless telephone instrument, which within the cellular/wireless network/system is personally assigned to the user and likely to be used in another system.
Personalized features of a home base network/system are provided to the traveling telephone user in using a telephone instrument in another network/system with a different exchange in which the user enters a code and a personal identification number (PIN) to any telephone instrument of a foreign system. The personalized features are retrieved from a national database, as described in U.S. Pat. No. 4,899,373, and used to provide the telephone user with his specialized features. In another aspect the features are encoded on a card which features are conveyed to the network database. Unfortunately from the point of view of a cellular/wireless telephone instrument the process does not make a C/W telephone instrument operative in a foreign network/system as opposed to providing familiar home type features to the user of a telephone instrument of a different system from the home system.
Various approaches have been proposed for making a foreign telephone user feel familiar with local telephone operations by providing features and functions such as they are accustomed to at home, but all have involved a using a special xe2x80x9cuniversalxe2x80x9d telephone instrument or are limited to providing system features such as are available to a user in his home network/system. Yet to be addressed is the ability of the visitor to the system to use his own C/W telephone instrument in a new different C/W network/system. This is particularly critical in the instance of cellular/wireless, since the user prefers to use his/her own C/W telephone instrument, which he/she is accustomed to.
A cellular/wireless (C/W) foreign subscriber/user, when roaming beyond a local cellular/wireless (C/W) network/system, compatible with his/her telephone instrument, is enabled to use her/his own cellular/wireless telephone instrument by entry of a code and a PIN into the foreign network/system desired to be used. The local serving C/W network/system algorithmically responds to the code and PIN by changing signal processing characteristics of the radio equipment of the network/system to accommodate operation of the subscriber""s cellular/wireless telephone instrument with the foreign network/system desired to be used.
In a particular embodiment of the invention, the foreign user has been assigned an InterSystem Roamer Access Code Number (IRACN) and Personal Identification Number (PIN). This permits use of the C/W network/system upon application, followed by validation, to a C/W network/system designed to accommodate foreign subscriber telephone instruments. The radio communication system of the responds to the transmitted IRACN and PIN by adjusting its interfacing and signal processing equipment to interact with the cellular/wireless telephone instrument of the subscriber.
In operation the local C/W network/system receives the IRACN and PIN and upon validation detects and characterizes the signals transmitted by the subscriber""s C/W telephone instrument and adjusts the receiver of the radio system to change the received signal to a format and character adjusted to the network/system operation requirements. Once identity and authentication is established the call may proceed normally. Reply downlink signals are changed to a format and character acceptable to the C/W telephone instrument prior to transmission.
In a specific embodiment, a foreign C/W subscriber requests service in the local C/W network/system, by using the cellular/wireless access channel and transmits the PIN and the IRACN to the central office (CO) of the local C/W network/system. The received signal is detected and characterized. A determination is made if it is a foreign or US (local) C/W service request, depending upon the C/W telephone instrument used. For US based C/W telephone instrument calls the process of registration and authentication proceeds as normal. For calls made using a foreign C/W telephone instrument, the received signal is characterized to determine if it is a GSM, TDMA, FDMA, PCS, etc. The signal is channeled to the appropriate radio system for that particular modulation and processing scheme. The uplink signal is frequency translated, and demodulated; it is decrypted and decoded, protocol converted, and deframed; it is subsequently structured and framed, modulated, frequency translated and adapted to NA (North American)-digital or analog radio system requirements in the local Central Office (CO).
Registration and authentication is initially performed to validate the subscriber PIN, IRACN and his/her identity. Transmitters of Invalid PIN and IRACN numbers are asked to check the numbers and try again. Valid subscriber entries are given a request acknowledgement to access the network and start transmitting. For a US based call, with a C/W telephone instrument designed for the local C/W network/system, registration and authentication follows normal operating procedure.